{
  "annotation_id": "b0fa49e7-74f5-436d-927d-d6aa86c10d47",
  "date_created": "2026-03-02T18:01:56.612000Z",
  "date_modified": "2026-03-02T18:01:56.612000Z",
  "file_hash": "670caef90c6df347be78ff30f3339cf0fc5cb2afe4043a4a867442217abbce21",
  "private": false,
  "record": {
    "abstract": "Bipartite entanglement may be reduced if there are restrictions on allowed\nlocal operations. We introduce the concept of a generalized superselection rule\n(SSR) to describe such restrictions, and quantify the entanglement constrained\nby it. We show that ensemble quantum information processing, where elements in\nthe ensemble are not individually addressable, is subject to the SSR associated\nwith the symmetric group (the group of permutations of elements). We prove that\neven for an ensemble comprising many pairs of qubits, each pair described by a\npure Bell state, the entanglement per element constrained by this SSR goes to\nzero for a large number of elements.",
    "arxiv_id": "quant-ph/0303140",
    "authors": [
      "Stephen D. Bartlett",
      "H. M. Wiseman"
    ],
    "categories": [
      "quant-ph"
    ],
    "doi": "10.1103/PhysRevLett.91.097903",
    "journal_ref": "Phys. Rev. Lett. 91, 097903 (2003)",
    "title": "Entanglement constrained by superselection rules",
    "url": "https://arxiv.org/abs/quant-ph/0303140"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "ab241d06-1bbb-40c8-94c6-d1b6426794b5",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}